title: Breaking prolonged sitting reduces postprandial glycemia in healthy, normal-weight adults: a randomized crossover trial.
abstract: BACKGROUND
  Sedentary behavior is a risk factor for cardiometabolic disease. Regularly interrupting sedentary behavior with activity breaks may lower this risk.
  
  
  OBJECTIVE
  We compared the effects of prolonged sitting, continuous physical activity combined with prolonged sitting, and regular activity breaks on postprandial metabolism.
  
  
  METHODS
  Seventy adults participated in a randomized crossover study. The prolonged sitting intervention involved sitting for 9 h, the physical activity intervention involved walking for 30 min and then sitting, and the regular-activity-break intervention involved walking for 1 min 40 s every 30 min. Participants consumed a meal-replacement beverage at 60, 240, and 420 min.
  
  
  RESULTS
  The plasma incremental area under the curve (iAUC) for insulin differed between interventions (overall P < 0.001). Regular activity breaks lowered values by 866.7 IU · L(-1) · 9 h(-1) (95% CI: 506.0, 1227.5 IU · L(-1) · 9 h(-1); P < 0.001) when compared with prolonged sitting and by 542.0 IU · L(-1) · 9 h(-1) (95% CI: 179.9, 904.2 IU · L(-1) · 9 h(-1); P = 0.003) when compared with physical activity. Plasma glucose iAUC also differed between interventions (overall P < 0.001). Regular activity breaks lowered values by 18.9 mmol · L(-1) · 9 h(-1) (95% CI: 10.0, 28.0 mmol · L(-1) · 9 h(-1); P < 0.001) when compared with prolonged sitting and by 17.4 mmol · L(-1) · 9 h(-1) (95% CI: 8.4, 26.3 mmol · L(-1) · 9 h(-1); P < 0.001) when compared with physical activity. Plasma triglyceride iAUC differed between interventions (overall P = 0.023). Physical activity lowered values by 6.3 mmol · L(-1) · 9 h(-1) (95% CI: 1.8, 10.7 mmol · L(-1) · 9 h(-1); P = 0.006) when compared with regular activity breaks.
  
  
  CONCLUSIONS
  Regular activity breaks were more effective than continuous physical activity at decreasing postprandial glycemia and insulinemia in healthy, normal-weight adults. This trial was registered with the Australian New Zealand Clinical Trials registry as ACTRN12610000953033.
authors.affiliation: Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
authors.forename: Meredith C
authors.initials: MC
authors.lastname: Peddie
authors.forename: Julia L
authors.initials: JL
authors.lastname: Bone
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Rehrer
authors.forename: C Murray
authors.initials: CM
authors.lastname: Skeaff
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Gray
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Perry
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001628:Beverages; D001786:Blood Glucose / Q000032:analysis*; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000517:prevention & control; D018592:Cross-Over Studies; D004032:Diet; D015444:Exercise; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D009520:New Zealand; D019518:Postprandial Period; D012307:Risk Factors; D057185:Sedentary Behavior; D013997:Time Factors; D014280:Triglycerides / Q000097:blood; D016138:Walking; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides